Apparatus and method of patterning sheet material

ABSTRACT

Apparatus for brush patterning a synthetic sheet material including a pair of parallel rollers, one of which is a buffing wheel rotated independently of means for transporting the sheet material and the other of which is a pressure roller with an outer elastomeric surface layer containing irregularly shaped indentations around its circumference and positioned at an interval from the buffing wheel roller sufficient to exert a corresponding irregular pressure on the surface being brushed. The apparatus and method further include means for applying a finish coating liquid while transporting the sheet material between the two rollers.

waited States Patent Bayer et al.

APPARATUS AND METHOD OF PATTERNING SHEET MATERIAL Inventors: BerndBayer, Elsenfeld; Alexander Hubert, Owrth am Main; Werner Riess,Erlenbach; Helmut Schaefer; Hans Wetteroth, both of Elsenfeld, all ofGermany Glanzstoff AG, Wuppertal, Germany Filed: Apr. 5, 1971 Appl. No.:131,039

Assignee:

Foreign Application Priority Data Apr. 3, 1970 Germany G 70 12 216.6

US. Cl 117/10, 117/64, 117/65.2, 118/206, 118/249 Int. Cl B44d 1/14Field of Search 117/10, 64 R, 65.2; 118/44, 104, 116, 117, 206, 249

References Cited UNITED STATES PATENTS 9/1937 ,lennett 117/10 1,949,3842/1934 Weyner.... 117/64 R 2,758,036 8/1956 Cyr 117/10 2,971,857 2/1961Baxter 117/10 Primary ExaminerWilliam D. Martin AssistantExaminer-Theodore G. Davis Attorney-Johnston, Root, O'Keeffe, Keil,Thompson & Shurtleff [57] ABSTRACT Apparatus for brush patterning asynthetic sheet material including a pair of parallel rollers, one ofwhich is a buffing wheel rotated independently of means for transportingthe sheet material and the other of which is a pressure roller with anouter elastomeric surface layer containing irregularly shapedindentations around its circumference and positioned at an interval fromthe buffing wheel roller sufficient to exert a corresponding irregularpressure on the surface being brushed. The apparatus and method furtherinclude means for applying a finish coating liquid while transportingthe sheet material between the two rollers.

7 Claims, 4 Drawing Figures PATENTEUUBTSO 191a INVENTORS: BERND BAYERALEXANDER HUBERT WERNER l ss HELMUT SCHAEFER HANS WETTEROTH ATT'YSAPPARATUS AND METHOD OF PATTERNING SHEET MATERIAL It has previously beenfound desirable to achieve cloud-like shades or patterns, sometimesreferred to as a brush patterning effect, in the finishing of a numberof synthetic sheet materials, including porous or non-porous sheets orsubstrates having a relatively smooth surface and employed, for example,as the leg or shank materials in finished products such as shoes. Thus,various artificial leather materials are readily available in bothporous and non-porous form with reference to the surface to be colorfinished. In the conventional finishing of the final articles, it hasbeen quite conventional to spray on the finished coat by hand, forexample onto the outer surface of an assembled shoe or boot, after whichthe coated finish is non-uniformly brushed off by hand. This procedureis quite expensive in terms of the time and effort required, andmoreover, the achievement of a brush patterning effect by hand requiresa very high degree of skill on the part of the individual finisher doingthe work.

One object of the present invention is to produce this brush patterningtype of effect of different shades, tints or nuances on the outersurface of artificial leather sheet materials or similar flexiblesynthetic sheet materials. More particularly, it is an object of theinvention to produce such patterning not on the final article such as ashoe or the like, but instead on the initial sheet material before it isfabricated into the final article. Another object of the invention is toachieve this patterning effect of the sheet material as it is beingwound and- /or unwound from appropriate take-up or feed spools. Stillanother object of the invention is to provide suitable apparatus and anoperating method which are easily and economically carried out so as toachieve a brush patterning effect which is commercially acceptable andsubstantially equivalent to that achieved by hand. Other objects andadvantages of the invention will become more apparent upon considerationof the following detailed disclosure.

It has now been found, in accordance with the invention, that one canachieve a very effective device or apparatus for the brush patterning ofa flexible, smoothsurfaced, synthetic sheet material by those elementswhich include in combination a first buffing wheel roller rotatablymounted for driven rotation and adapted to be coated on its outerperipheral surface with a buffing wax, a second pressure rollerrotatably mounted on an axis parallel to the axis of said first rollerand at an adjustable interval therefrom for application of pressure on alength of said sheet material passed between the rollers, said secondroller having an outer elastomeric surface layer containing irregularlyshaped indentations around its entire circumference, means to transportthe sheet material in a path between the parallel rollers independentlyof said first driven roller, and means to apply a finish coating liquidonto the surface of the sheet material being brush patterned.

The apparatus and method of the invention are explained in greaterdetail in conjunction with the accompanying drawing in which FIG. 1 is aperspective view with certain portions omitted of a typical buffingwheel roller used for purposes of the present invention;

FIG. 2 is another perspective view showing the combination of thebufiing wheel roller and the pressure roller of FIGS. 1 and 3 inoperative contact with a sheet material being patterned;

FIG. 3 is a perspective view of a pressure roller according to theinvention which is somewhat enlarged in comparison to FIG. 2 and FIG. 4is a schematic flow-sheet diagram of the overall apparatus according tothe invention, including a preferred sequence of operations.

Referring first to FIG. 1, the buffing wheel roller 1 illustrated by wayof example consists of a large number of cotton twill discs or annularsheets or layers 2 mounted on a spindle or drive shaft 3 and compressedor held together by suitable flanges 4 at either end of thecylindrically-shaped roll. The intermediate portions of the fabric discs2 have been omitted in FIG. 1 in order to more clearly point out thefact that a layered construction is especially preferred. These discs 2can of course consist of other equivalent materials, for example wool,linen, leather, or other similar fibrous materials.

It will be understood that this buffing wheel is a relativelyconventional element commonly employed to achieve a very mild abradingor polishing action as applied to leathers or other sheet materials. Thepresent invention does not reside in the construction of the particularbuffing wheel roller but rather in the manner in which it is combinedand used in the apparatus of the invention. It has been found to be mostconvenient to work with a buffing wheel roller in which the outerdiameter is about 30 cm. while its length or effective working width isabout 1 meter. In order to prevent excessive abrasion or too rapid aloss of fibers from the peripheral surface of the buffing wheel roller,it is desirable to apply a typical buffing wax onto the outer surface ofthe buffing roller. Such buffing waxes are quite well known and includea wide variety of organic materials, especially hydrocarbons, thesubstances usually being a solid at normal temperatures and providing acertain lubricating action and a means of effectively retaining thefibers on the buffing wheel without being rapidly abraded or throwntherefrom. Thus, for purposes of the invention, it is possible to applyany conventional buffing wax or lubricant, preferably by means of anoscillating and evenly pressed wax bar or rod.

In FIG. 3, one embodiment of a pressure roller 5 as an essential elementof the present invention includes an outer elastomeric layer or coatingof a rubberyelastic material 6 in which there are providedirregularly-shaped indentations 7 around the entire circumference of theroller. These indentations are preferably discontinuous, at least in acircular plane or segment around the periphery or the roller, and can beeasily cut into the outer surface or layer 6 of the elastomericmaterial, which may consist for example of natural rubber or varioussynthetic rubbers such as butyl rubber, Buna-S or Perbunan. At least onemounting spindle or shaft 8 is preferably provided so that the pressureroller 5 is not driven by its axial shaft but is free to rotate underthe action of an applied and transported sheet material.

The surface area of each of the individual indentations as well as theirtotal surface area naturally depends upon the specifically desiredpattern and can therefore be varied within wide limits. For example,individual indentations can be varied between limits of approximately 1to 20 cm. and the depth of the indentations is preferably about 1 to 3mm. These values represent an especially preferred range in eachinstance, and it will be understood that special circumstances mayrequire even wider variations.

FIG. 2 illustrates in partly schematic form the cooperative arrangementof the pair of rollers, i.e., the buffing wheel roller 1 and thepressure roller 5 as they are mutually applied to the sheet material 9being treated to achieve the desired brush patterning effect. Theoverall apparatus and procedure may also be reviewed in conjunction withthe schematic flow diagram of FIG. 4.

The buffing wheel roller 1 is preferably continuously coated withbuffing wax from the oscillating or reciprocating bar 10 pressed evenlyonto the peripheral surface of the buffing wheel. By way of example, thebuffing wheel roller 1 can be operated at a peripheral speed of about 75meters/minute opposite to the direction of travel of the sheet material9 being treated, and in general, it has been found preferable to operatebuffing wheels with a variable cylindrical diameter of to 30 cm. withinlimits of about 600 to 1,300 r.p.m. Again, this speed of the buffingwheel can also be varied within very wide limits, the optimum speedsbeing easily determined by a few preliminary tests. Since the individualfabric discs 2 making up the cylinder of the buffing wheel are graduallyabraded over a long period of operation, they are generally replacedafter they have been reduced to about 15 cm. in diameter from theiroriginal 30 cm. diameter.

The pressure roller 5 is adjustably mounted by any suitable adjustablemounting frame or guide member so as to be placed at a specific intervalfrom the buffing wheel roller 1. ln this manner, a specific pressingeffect is produced on the transported sheet of material as indicated bythe upward movement of the double-headed arrow on the center line ofshaft 8. In other words, a pressure is exerted by the roller 5 upwardlyagainst the underside of the sheet material 9 as the sheet material ispassed between the two rollers and is pressed slightly against or inslight buffing contact with the roller 1. The most advantageous amountof pressure is easily determined by the observed action of the brushingeffect.

It is especially preferred that the pressure roller 5 be adjustablyarranged with its axis parallel to that of the buffing wheel roller, butin such manner that this pressure roller can rotate quite freely underthe influence of the sheet material 9 being drawn thereover. Thus, thespeed of rotation of the pressure roller 5 is determined by the rate atwhich the sheet material is drawn between the two rollers against theopposing driven rotation of the buffing wheel roller 1. Thus, roller 5is essentially driven by the transported sheet material 9.

As shown even more schematically in FIG. 4, the sheet material 9 isfirst withdrawn from a feed spool 11 and drawn upwardly at an inclinedangle between the buffing wheel roller 1 and the pressure roller 5. Ifdesired, a pair of nip rollers or tensioning rollers 12 can be used toguide and/or tension the sheet material so that it is more smoothlywithdrawn and fed from the feed spool 11. As the sheet material 9 isdrawn up between the two rollers 1 and 5, a conventional liquid finishis applied thereto, preferably by spraying the liquid as shown at 13.Many finish coating liquids are available in this art to produce a brushpatterning effect, and such finishes generally comprise a liquidsolvent, a bonding agent and a dye or pigment component. The exactcomposition and specific materials employed in such finish coatingliquids do not constitute part of the present invention since they arequite common in this art. Adjustments can be made in their compositionsin order to achieve the desired rate of application, drying and the likeas is known.

As the sheet material 9 is brought between the motor-driven buffingwheel roller 1 and the pressure roller 5, it adapts itself to theelevated or depressed portions created by the indentations in theelastomeric layer of the pressure roller, so that at those points whichare relatively more elevated on the coated surface, the dyed orpigmented coating is partially brushed off depending upon the degree ofelevation. In other words, a more complete brushing off is achieved inthe relatively more elevated proportions in comparison to the depressedportions. Moreover, the edges or borders between elevated areas anddepressed areas resulting from the indentations 7 produce anintermediate effect where the finishing liquid is partially brushed offso that one area blurrs into the other to achieve the desired brushpatterning effect due to the resilient pressure exerted by differentareas of the pressure roller. Thus, even though the indentationsthemselves are quite sharply defined on the surface of the roller 5,there is a complete blending or shading of each distinctly brushed areaof the sheet material so that one effectively achieves a pattern ofdifferent shades or tints in a very desirable brushed effect.

The rate at which the sheet material 9 is drawn or transported over thepressure roller 5 in buffing contact with the roller 1 can likewise bevaried within relatively wide limits. In general, however, it isespecially preferred to transport this sheet material at a rate of lm/min to 10 m/min Again, the relative speeds as between the transportedsheet 9 and the roller 1 can be easily determined to achieve an optimumeffect by making a few simple routine variations in such speeds whilevisually observing the effect being obtained. By using a variable speedmotor to draw or transport the sheet material 9 onto the take-up spool14, or other conventional means can be employed in order to transportthe sheet material at a predetermined rate. As the sheet material 9emerges from the pair of parallel rollers 1 and 5, it can be conductedthrough a conventional heating or drying zone beneath any suitableheater or dryer 15, e.g. an infrared heating device, an air dryer or thelike. A supporting conveyor such as guide rollers 16 or similar meanscan be used to support the relatively flexible sheet material until itis taken up on the spool 14. When the liquid finish coat contains a veryvolatile solvent and is substantially self-drying, the heating zone canbe eliminated and/or the drying zone can be quite short. The rate ofdrying also depends upon the thickness of the finished coat after it hasbeen brushed, and it will be apparent that a substantial amount ofexcess liquid should be avoided in achieving a uniform brush patterningeffect. In this respect, it should be noted that a uniform effect isdesired in the sense that there is a uniform pattern caused by theirregular indentations in the pressure roller 5. It is feasible, ofcourse, to employ a more regular pattern of indentations so as toachieve a more distinctive and regular design in the finished material.However, the brush patterning effect in which there is a seeminglyrandom and irregular blending or shading of the finished color is muchmore desirable.

The interval between the pressure roller 5 and the buffing wheel roller1 can be gradually changed by hand as the wheel 1 is gradually worn downover a long period of treatment, or if desired, this gradual reductionof the interval can also be made automatically based upon a certaindegree of operating experience. Also, either the buffing wheel 1 or thepressure roller may be spring-tensioned or spring-balanced to achieve asubstantially constant interval at all times. In general, very littlepressure is exerted by the buffing wheel roller 1 onto the surface ofthe sheet material 9 as it passes over roller 5, and especially goodresults are achieved if this roller 1 primarily or exclusively acts as abuffing element to brush off portions of the coated surface of the sheetmaterial, thereby permitting the pressure roller 5 to continuouslyregulate the particular areas in which more or less of the freshlyapplied coating liquid is being removed. Thus, the patterning effect isnot achieved by regulating the pressure of the buffing or brushingelement, but instead is achieved by the differ ence in back pressureexerted by the roller 5 due to the difference in size and location ofthe indentations therein.

The apparatus of the invention has been applied to many different porousand non-porous synthetic sheet materials having a relatively smoothsurface as distinguished from a highly textured or typical piled textilesurface. The invention is particularly applicable to the finish coatingor brushed coating of artificial leather materials, e.g., in which abonded or impregnated fibrous fleece or non-woven web has been providedwith a polyvinyl chloride or polyurethane surface coating so as toprovide a very flexible and relatively elastic sheet material quitesimilar to natural leather. The thickness of the sheet material canrange between about 0.5 mm to 3 mm it again being understood that suchparameters may be widely varied in combination with similar variationsin the buffing wheel roller and especially the pressure roller. Thespecific method of applying the liquid finishing coat prior to treatmentwith the rollers of the invention as well as other steps in the overallprocess may be varied and adapted to specific circumstances withoutdeparting from the spirit or scope of the invention.

The invention is hereby claimed as follows:

1. Apparatus for the brush patterning of a flexible, smooth-surfaced,synthetic sheet material which comprises:

a buffing wheel roller as a first roller rotatably mounted for drivenrotation in brushing contact with said sheet material and adapted to becoated on its outer peripheral surface with a buffing wax;

a pressure roller as a second roller freely rotatably mounted on an axisparallel to the axis of said first roller and at an adjustable intervaltherefrom for application of back pressure by said second roller againstone side of said sheet material passed be tween the rollers, said secondroller having an outer elastomeric surface layer containing irregularlyshaped indentations around its entire circumference, whereby said sheetmaterial adapts itself to the elevated and depressed portions created bythe indentations such that those points which are relatively moreelevated on the surface of the sheet material being coated with afinishing liquid are more completely brushed off by contact with saidfirst roller;

means to transport the sheet material in a path between the parallelrollers independently of both said buffing wheel roller and saidpressure roller; and

means to apply a finish coating liquid onto the surface of the sheetmaterial coming into contact with said buffing wheel roller.

2. Apparatus as claimed in claim 1 wherein said buffing wheel roller iscomposed of a large number of soft, abradable fibrous discs mountedtogether in compressed cylindrical shape on a common spindle and whereinthe outer layer of said pressure roller consists essentially of anatural or synthetic rubber.

3. Apparatus as claimed in claim 1 including means to apply a buffingwax onto said buffing wheel roller.

4. Apparatus as claimed in claim 1 including means to dry the finishcoated and brushed surface of the sheet material after it has passedbetween said rollers.

5. Apparatus as claimed in claim 1 including means to spray said finishcoating liquid onto the surface of the sheet material as it is beingtransported between said rollers.

6. A method of brush patterning a flexible, smoothsurfaced, syntheticsheet material which comprises first applying a liquid finishing coatonto the surface of said sheet material to be brush patterned and thentransporting the liquid coated sheet material over a freely rotatablepressure roller for contact with an elastomeric circumferential surfacelayer of said roller containing irregularly-shaped indentations in orderto exert a correspondingly irregular pressure against the sheetmaterial, applying a buffing wheel roller to the opposite side of saidsheet material in axially parallel relation to said pressure roller withthe outer circumferential surface of said buffing roller being rotatedin a direction opposite to the direction of travel of the transportedsheet material, thereby irregularly brushing off the applied liquidfinishing coat as between elevated and depressed portions irregularlyimparted by the pressure roller to said sheet material.

7. A method as claimed in claim 6 wherein said sheet material is anartificial leather.

i UNITED STATES PATENT OFFICE I ERTIFICATE 0F fiOERECTIGN Q PATENT NO.3,769,058

DATED October 30, 1973 INVENTOR( 1 Bernd Bayer et a].

It is certified that error appears in the above-identified patent andthat said Letters Patent 0 are hereby corrected as shown below:

In Column 1, Line 32, delete "of" and substitute -o nq Signed and?Sealed thie Twenty-eighth 0; September 1976 [SEAL] Arrest:

RUTH C. MASON C. MARSHALL DANN Arresting Officer (nmmissinm'r ujPatenrsand Trademarks

2. Apparatus as claimed in claim 1 wherein said buffing wheel roller iscomposed of a large number of soft, abradable fibrous discs mountedtogether in compressed cylindrical shape on a common spindle and whereinthe outer layer of said pressure roller consists essentially of anatural or synthetic rubber.
 3. Apparatus as claimed in claim 1including means to apply a buffing wax onto said buffing wheel roller.4. Apparatus as claimed in claim 1 including means to dry the finishcoated and brushed surface of the sheet material after it has passedbetween said rollers.
 5. Apparatus as claimed in claim 1 including meansto spray said finish coating liquid onto the surface of the sheetmaterial as it is being transported between said roLlers.
 6. A method ofbrush patterning a flexible, smooth-surfaced, synthetic sheet materialwhich comprises first applying a liquid finishing coat onto the surfaceof said sheet material to be brush patterned and then transporting theliquid coated sheet material over a freely rotatable pressure roller forcontact with an elastomeric circumferential surface layer of said rollercontaining irregularly-shaped indentations in order to exert acorrespondingly irregular pressure against the sheet material, applyinga buffing wheel roller to the opposite side of said sheet material inaxially parallel relation to said pressure roller with the outercircumferential surface of said buffing roller being rotated in adirection opposite to the direction of travel of the transported sheetmaterial, thereby irregularly brushing off the applied liquid finishingcoat as between elevated and depressed portions irregularly imparted bythe pressure roller to said sheet material.
 7. A method as claimed inclaim 6 wherein said sheet material is an artificial leather.